@import url(https://a.amap.com/jsapi_demos/static/demo-center/css/demo-center.css);
#container {
  width: 100vw;
  height: 100vh;
}
.three {
  width: 200px;
  height: 200px;
  position: fixed;
  top: 10px;
  right: 10px;
  z-index: 999;
  background-color: aliceblue;
}

body {
  background: #000;
}
button {
  position: absolute;
  left: 0;
  right: 0;
  margin: auto;
  z-index: 2;
  top: 0;
}
